1. Field of the Invention
The invention relates generally to concrete finishing trowels and, more particularly, to a transport system for a powered finishing trowel. The invention additionally relates to a concrete finishing trowel, such as a riding trowel, having a transport system that allows unassisted manual movement of the trowel.
2. Description of the Related Art
A variety of machines are available for smoothing or otherwise finishing wet concrete. These machines range from simple hand trowels, to walk-behind trowels, to self-propelled riding trowels. Regardless of the mode of operation of such trowels, the powered trowels generally include one to three rotors that rotate relative to the concrete surface.
Riding concrete finishing trowels can finish large sections of concrete more rapidly and efficiently than manually pushed or guided hand-held or walk behind finishing trowels. Riding concrete finishing trowels typically include a frame having a cage that generally encloses two, and sometimes three or more, rotor assemblies. Each rotor assembly includes a driven shaft and a plurality of trowel blades mounted on and extending radially outwardly from the bottom end of the driven shaft. The driven shafts of the rotor assemblies are driven by one or more engines mounted on the frame and typically linked to the driven shafts by gearboxes of the respective rotor assemblies.
The weight of the finishing trowel, including the operator, is transmitted frictionally to the concrete surface by the rotating blades, thereby smoothing the concrete surface. The pitch of individual blades can be altered relative to the driven shafts via operation of a lever and/or linkage system during use of the machine. Such a construction allows the operator to adjust blade pitch during operation of the power trowel. As commonly understood, blade pitch adjustment alters the pressure applied to the surface being finished by the machine. This blade pitch adjustment permits the finishing characteristics of the machine to be adjusted. For instance, in an ideal finishing operation, the operator first performs an initial “floating” operation in which the blades are operated at low speeds (on the order of about 30 rpm) but at high torque. Then, the concrete is allowed to cure for another 15 minutes to one-half hour, and the machine is operated at progressively increasing speeds and progressively increasing blade pitches up to the performance of a finishing or “burning” operation at the highest possible speed—preferably above about 150 rpm and up to about 200 rpm.
During use, the riding trowel is supported by the engagement between the number of blades and the underlying concrete material. To some extent, the weight of the machine assists the finishing process. Although the weight of the machine can be beneficial for providing efficient, robust, and powerful trowel operation, the weight of the machine is also detrimental to non-use transportation of the trowel, i.e. while moving the trowel to or from a worksite without operating the blades. Commonly, supplemental equipment, such as a skid loader, a backhoe, or the like, is utilized to move the machine to and from a work surface. Some concrete finishing trowels are fitted with lift points for attachment to a chain for this purpose. Alternatively, when no such equipment is available or the trowel must be used in a location which is not accessible by such equipment, two or more laborers are required to manually lift and move the machine. This is a labor some and physically demanding means of moving such machines.
Previous trowel transport systems have been disclosed which include a number of retractable wheels or casters that are securable to the frame of the trowel. One such system is a removable wheel kit or dolly disclosed in U.S. Pat. No. 5,238,323 to Allen et al. The wheel kit disclosed in the Allen '323 patent includes a pair of wheel assemblies secured to generally opposite sides of the exterior of the cage of a riding trowel. A separate jack is provided for each wheel assembly so that each jack independently raises and lowers a separate wheel assembly relative to the frame. When lowered, the wheels support the trowel such that a single user can move the entire trowel by simply pushing or pulling it in an intended direction. Although such systems enhance the mobility of power trowels, they are not without their drawbacks.
For instance, because the wheel assemblies of the Allen '323 patent are located outboard of the cage, they increase the overall footprint of the machine. Increasing the footprint of the machine increases the space occupied by the machine. Accordingly, it may prevent the machine from being transported in the beds of some trucks without removing the wheel assemblies. Increasing the footprint of the machine also detracts from a user's ability to position the machine close to the perimeter of a pour area or an obstacle in a pour area. This is problematic because users of finishing machines prefer that the machine finishes as much of the work surface as possible to reduce the need for hand work. In enclosed spaces, the wheel assemblies disclosed in the '323 patent, being positioned outside a normal footprint of the machine, are exposed to the obstacles, such as walls, posts, or the like, and thus increase an offset between an outer edge of the machine and an outer edge of the area finished by the blades. The areas that cannot be finished due to the interference between the wheel assemblies and the obstructions must be finished by hand, increasing the amount of hand work associated with a given pour. This problem can be avoided only by removing the wheel assemblies prior to commencing a finishing operation.
Transport systems such as the one disclosed in U.S. Pat. No. 5,238,323 are also relatively inefficient. To raise the machine, the operator must operate two separate jacks on opposite sides of the machine. In addition, unless care is taken to operate both jacks the same amount, one side of the machine may be higher than the other during transport, reducing the stability and maneuverability of the machine.
Accordingly, there is also a need for a transport system for a concrete finishing trowel that requires less effort than previously-known transport systems to be converted between a stowed position and a deployed operational position. There is also a need for an easily deployed concrete finishing trowel transport system that does not unnecessarily increase the footprint of the machine. It is further desired to provide a trowel transport system that can be implemented into a number of machine configurations as well as one that is relatively simple to operate, inexpensive to produce, and simple to maintain.